Past performance is no guarantee of future returns, yet if I could only pick two autographs to invest in, I would choose Neil Armstrong/the Apollo 11 crew and the Beatles.

Photos signed by all three Apollo 11 crewmembers have grown in value by 13.7% a year since 2000 to �12,000. As we approach the 50th anniversary of the first Moon landing, in 2019, I expect demand for their autographs to increase substantially - pushing prices higher.

The Beatles are an evergreen investment - both individually and as a whole. Each new generation falls in love with them and wants their memorabilia. They will always be the world's most famous band. Autographs of all the Fab Four on one page have grown by 8.7% a year since 2000, and now stand at �9,500.